Rotary printing machines, and particularly web-type rotary printing machines, usually are driven by a horizontal main drive shaft. This main drive shaft is retained in bearings and has transmission elements to drive the individual printing machine units or stations. The transmissions have individual drive motors associated therewith and clutches permit, selectively, engagement or disengagement of the individual printing machine units with the main drive shaft. The printing machine units, thus, can be driven independently from each other by the individual drive units so that some drive units which are not clutched-in can have service or make-ready operations associated therewith. Usually, energy transmission of the drive motors to the main drive shaft is obtained by gears, toothed or gear belts, or by flat belts. The energy is then transmitted over vertical or horizontal shafts, coupled from the motors by bevel gears or the like for engagement with the respective printing machine units. The main drive shaft also functions as a synchronizing shaft for those printing machine units which are coupled thereto.
German Patent 975,145, Bayer, assigned to a predecessor company of the assignee of the present application, shows a drive for a rotary web-fed printing machine in which individual printing stations are serially arranged. The printing machine units or stations have individual electric motors associated therewith, which are coupled to a plurality of main drive shafts. The individual printing units are driven by vertical drive shafts which can be selectively coupled to the main drive shaft. The arrangement permits selectively stopping printing units, including accessory or auxiliary apparatus, while the inkers continue to rotate. This arrangement is not suitable for vertically stacked printing machine units or printing towers because it is too expensive and requires a substantial number of equipment components.
U.S. Pat. No. 4,240,346, Landis et al., describes a drive for a rotary web press printing machine which is serially constructed, in which each printing machine station has a drive motor associated therewith which can be connected to a horizontal main drive shaft by a suitable clutch.
When printing machine stations are located above each other, the drives with horizontal and vertical shafts require substantial numbers of drive wheels or gears. Use of a large number of drive wheels or gears, intermediate gears and the like, particularly bevel gears, results in play which causes difficulties to maintain register within an entire machine system built of a plurality of printing machine units, and results in register errors which can be corrected only with great difficulty and require apparatus of extreme accuracy.